It is known a vehicle provided with a differential gear device that transmits power from a driving source to a right driving wheel and a left driving wheel with allowing a relative rotation therebetween. Such a differential gear device for a vehicle generally comprises a differential case, a pinion shaft, side gears and pinion gears. The differential case is drivably rotated by power from a power source of the vehicle to transmit the power from the power source to the right and left driving wheels, with allowing relative rotation of the right and left driving wheels. The pinion shaft of a cylindrical shape is fixed to the differential case in the direction orthogonal to the rotational axis thereof The side gears are provided in the differential case coaxially with the rotational axis thereof in an opposing manner intervening the pinion shaft, to be rotated with the right and left driving wheels. The pinion gears are rotatably supported by the pinion shaft. Patent Document 1 discloses one example of the differential gear device for the vehicle.
Patent Document 1: Japanese Patent Publication No. 9-303533